Bottom Line: Stress-related disorders brought on by traumatic or stressful life events were associated with increased risk of developing an autoimmune disease.

Why The Research Is Interesting: Development of stress-related disorders such as posttraumatic stress disorder (PTSD) may influence multiple bodily systems, including immune function. Whether this contributes to risk for autoimmune disease remains unclear.

Who and When: 106,464 patients in Sweden diagnosed with stress-related disorders between 1981-2013 and compared with 126,652 of their siblings and nearly 1.1 million individuals without stress-related disorders.

What (Study Measures and Outcomes): Diagnosis of stress-related disorders, such as PTSD, acute stress reaction, adjustment disorder and other stress reactions (exposures); development of 41 autoimmune diseases, such as rheumatoid arthritis, psoriasis, Crohn disease and celiac disease (outcomes)

How (Study Design): This was an observational study. Researchers were not intervening for purposes of the study and cannot control all the natural differences that could explain the study findings.

Results: A stress-related disorder was associated with an increased risk of a subsequent autoimmune disease compared with siblings and other individuals without stress-related disorders.

Study Limitations: Diagnoses from primary care aren't included in a Swedish patient register, which could result in fewer stress-related disorders and autoimmune diseases being detected, particularly when the conditions are less severe.

Study Conclusions: More studies are needed to understand possible reasons behind the association of stress-related disorders and the development of autoimmune diseases.

To Learn More: The full study is available on the For The Media website.

(doi:10.1001/jama.2018.7028)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

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